The wireless market has experienced a remarkable development and growth since the introduction of the first modern mobile phone systems, with a steady increase in the number of subscribers, new application areas, and higher data rates. As mobile phones and wireless connectivity have become consumer mass markets, the prime goal of the IC manufacturers is to provide low-cost solutions. The power amplifier (PA) is a key building block in all RF transmitters. To lower the costs and allow full integration of a complete radio System-on-Chip (SoC), it is desirable to integrate the entire transceiver and the PA in a single CMOS chip. While digital circuits benefit from the technology scaling, it is becoming harder to meet the stringent requirements on linearity, output power, bandwidth, and efficiency at lower supply voltages in traditional PA architectures. This has recently triggered extensive studies to investigate the impact of different efficiency enhancement and linearization techniques, like polar modulation and outphasing, in nanometer CMOS technologies. This thesis addresses the potential of integrating linear and power-efficient PAs in nanometer CMOS technologies at GHz frequencies. In total eight amplifiers have been designed - two linear Class-A PAs, two switched Class-E PAs, and four Class-D PAs linearized in outphasing configurations. Based on the outphasing PAs, amplifier models and predistorters have been developed and evaluated for uplink (terminal) and downlink (base station) signals. The two linear Class-A PAs with LC-based and transformer-based input and interstage matching networks were designed in a 65nm CMOS technology for 2.4GHz 802.11n WLAN. For a 72.2Mbit/s 64-QAM 802.11n OFDM signal with PAPR of 9.1dB, both PAs fulfilled the toughest EVM requirement in the standard at average output power levels of +9.4dBm and +11.6dBm, respectively. The two PAs were among the first PAs implemented in a 65nm CMOS technology. The two Class-E PAs, intended for DECT and Bluetooth, were designed in 130nm CMOS and operated at low ‘digital’ supply voltages. The PAs delivered +26.4 and +22.7dBm at 1.5V and 1.0V supply voltages with PAE of 30% and 36%, respectively. The Bluetooth PA was based on thin oxide devices and the performance degradation over time for a high level of oxide stress was evaluated. The four Class-D outphasing PAs were designed in 65nm, 90nm, and 130nm CMOS technologies. The first outphasing design was based on a Class-D stage utilizing a cascode configuration, driven by an AC-coupled low-voltage driver, to allow a 5.5V supply voltage in a 65nm CMOS technology without excessive device voltage stress. Two on-chip transformers combined the outputs of four Class-D stages. At 1.95GHz the PA delivered +29.7dBm with a PAE of 26.6%. The 3dB bandwidth was  1.6GHz, representing state-of-the-art bandwidth for CMOS Class-D RF PAs. After one week of continuous operation, no performance degradation was noticed. The second design was based on the same Class-D stage, but combined eight amplifier stages by four on-chip transformers in 130nm CMOS to achieve a state-of-the-art output power of +32dBm for CMOS Class-D RF PAs. Both designs met the ACLR and modulation requirements without predistortion when amplifying uplink WCDMA and 20MHz LTE signals. The third outphasing design was based on two low-power Class-D stages in 90nm CMOS featuring a harmonic suppression technique, cancelling the third harmonic in the output spectrum which also improves drain efficiency. The proposed Class-D stage creates a voltage level of VDD/2 from a single supply voltage to shape the drain voltage, uses only digital circuits and eliminates the short-circuit current present in inverter-based Class-D stages. A single Class-D stage delivered +5.1dBm at 1.2V supply voltage with a drain efficiency and PAE of 73% and 59%, respectively. Two Class-D stages were connected to a PCB transformer to create an outphasing amplifier, which was linear enough to amplify EDGE and WCDMA signals without the need for predistortion. The fourth outphasing design was based on two Class-D stages  connected to an on-chip transformer with peak power of +10dBm. It was used in the development of a behavioral model structure and model-based phase-only predistortion method suitable for outphasing amplifiers to compensate for both amplitude and phase mismatches. In measurements for EDGE and WCDMA signals, the predistorter improved the margin to the limits of the spectral mask and the ACLR by more than 12dB. Based on a similar approach, an amplifier model and predistortion method were developed and evaluated for the +32dBm Class-D PA design using a downlink WCDMA signal, where the ACLR was improved by 13.5dB. A least-squares phase predistortion method was developed and evaluated for the +30dBm Class-D PA design using WCDMA and LTE uplink signals, where the ACLR was improved by approximately 10dB.

Cognitive radio is a new concept of reusing licensed spectrum in an unlicensed manner. Cognitive radio is motivated by recent measurements of spectrum utilization, showing unused resources in frequency, time and space. The spectrum must be sensed to detect primary user signals, in order to allow cognitive radios in a primary system. In this thesis we study some topics in spectrum sensing for cognitive radio. The fundamental problem of spectrum sensing is to discriminate samples that contain only noise from samples that contain a very weak signal embedded in noise. We derive detectors that exploit known structures of the signal, for the cases of an OFDM modulated signal and an orthogonal space-time block coded signal. We derive optimal detectors, in the Neyman-Pearson sense, for a few different cases when all parameters are known. Moreover we study detection when the parameters, such as noise variance, are unknown. We propose solutions the problem of unknown parameters. We also study system aspects of cognitive radio. More specifically, we investigate spectrum reuse of geographical spectrum holes in a frequency planned primary network. System performance is measured in terms of the achievable rate for the cognitive radio system. Simulation results show that a substantial sum-rate could be achieved if the cognitive radios communicate over small distances. However, the spectrum hole gets saturated quite fast, due to interference caused by the cognitive radios.

<p>Det här examensarbetet har utförts inom civilingenjörsutbildningen för Maskinteknik vid Linköpings tekniska högskola i samarbete med SB Truck AB. Syftet med examensarbetet var att undersöka ett antal truckmodeller för att bestämma infästningsbultarnas belastning samt hur spänningarna fördelas i de olika stativen. Infästningsbultarna håller ihop stativet och chassit.</p><p>För att kunna genomföra beräkningarna med varierande stativlängder har ett excel-blad utformats, där det är möjligt att beräkna både krafterna på infästningarna och den totala förskjutningen.</p><p>Belastningarna på modell TTFYI har beräknats både för hand och i Pro Mechanica. Resultaten för beräkningarna blev 3,9 kN respektive 3,7 kN. Resultat för övriga stativ finns tabellerade i resultatkapitlet.</p><p>Spänningarna blir generellt sett låga i samtliga stativ på den analyserade modellen. Gaffelvagnen utsätts för höga spänningskoncentrationer vid sammanfogningen mellan gaffelbenen och gaffelbröstet. För övriga stativ blir spänningskoncentrationerna relativt låga, med undantag från områdena där lasterna appliceras.</p>

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Det här examensarbetet har utförts inom civilingenjörsutbildningen för Maskinteknik vid Linköpings tekniska högskola i samarbete med SB Truck AB. Syftet med examensarbetet var att undersöka ett antal truckmodeller för att bestämma infästningsbultarnas belastning samt hur spänningarna fördelas i de olika stativen. Infästningsbultarna håller ihop stativet och chassit. För att kunna genomföra beräkningarna med varierande stativlängder har ett excel-blad utformats, där det är möjligt att beräkna både krafterna på infästningarna och den totala förskjutningen. Belastningarna på modell TTFYI har beräknats både för hand och i Pro Mechanica. Resultaten för beräkningarna blev 3,9 kN respektive 3,7 kN. Resultat för övriga stativ finns tabellerade i resultatkapitlet. Spänningarna blir generellt sett låga i samtliga stativ på den analyserade modellen. Gaffelvagnen utsätts för höga spänningskoncentrationer vid sammanfogningen mellan gaffelbenen och gaffelbröstet. För övriga stativ blir spänningskoncentrationerna relativt låga, med undantag från områdena där lasterna appliceras.

<p>This thesis work is divided into two parts that relate to each other. The first part investigates driving forces and limiting factors in the customisation of information on packaging and the second part focuses on how the customisation task should be performed in order to obtain high productivity and efficient logistics. Opportunities with hybrid printing solutions where conventional technology is combined with digital printing are discussed.The first of the included papers talks about the driving forces and limiting factors in the customisation of information on packaging and focuses on marketing aspects and consumer value. The second paper investigates the logistical aspects of using digital printing to add information on pre-printed packaging, with the primary focus on the opportunities to reduce changeover time and printing form costs. The third paper investigates how digital printing can be integrated into a packaging line and identifies critical productivity related parameters. These three papers are analysed together in this report, giving input to conclusions about the driving forces and limiting factors in the customisation of information on packaging and how the customisation task should be performed to obtain high productivity and efficient logistics. Hence, this thesis work does not originate solely in one discipline. Digital printing technology, logistics and marketing aspects are all considered to draw conclusions.</p><p>It is shown that it is possible to obtain marketing advantages, fulfill market demands better, get increased consumer value and reduced costs by using a hybrid printing solution. There exists at the same time a number of limiting factors, such as print quality demands, additional costs and reliability issues that are crucial to consider before concluding whether or not customisation of information on packaging would be successful in any given business scenario.</p><p>Different scenarios for where the customisation task can be inserted into a value chain are defined and discussed. Explicit studies of one of the scenarios are made. This scenario is defined as having a customisation task inline in a packaging line. The other scenarios, customisation at the packaging producer and customisation at the wholesaler/retailer, are not explicitly investigated, but it has been possible to discuss these scenarios as well through the research results obtained. The results show that there are factors that point towards the scenario where digital printing is performed at the producer as being the most beneficial. A number of critical productivity related factors for this scenario are identified in paper III, which gives guidelines on how to obtain high productivity when a digital printing task is integrated into a packaging line. It is finally shown that it is possible to obtain high delivery service and efficient logistics by using a hybrid printing solution. It is, however, of crucial importance that possible drawbacks be considered in order to accurately conclude whether a hybrid printing solution will be successful or not.</p>

The purpose of this master's thesis is to evaluate whether it is feasible to use the panchromatic band of Landsat 7 in order to improve the spatial resolution of colour images. The images are to be used as texture in visual databases for flight simulators and for this reason it is important that the fusion preserves natural colours. A number of methods for fusing panchromatic and multispectral images are discussed. Four of them are implemented and evaluated. The result is that standard methods such as HSI substitution are not suitable for this purpose since they do not preserve natural colours. However, if only high frequencies of the panchromatic image are used the resolution can be improved without noticeable colour distortion.